Fairlead



March 1965 w. P. ATKINSON ETAL 3,17

FAIRLEAD Filed April 16, 1962 2 Sheets-Sheet 1 3Y0 JJ 2 30 r m w FIG. 1

INVENTORS: WILLIAM PATKINSON 4 BRUNO LLONNGREN ATTORNEY March 1965 w. P.ATKINSON EI'AL 3,174,726

FAIRLEAD 2 Sheets-Sheet 2 Filed April 16, 1962 FIG. 5

INVENTORSI WILLIAM PATKINSON BRUNO LLONNGREN ATTORNEY United StatesPatent 3,174,726 FAIRLEAD William P. Atkinson and Bruno L. Lonngren,both of South Milwaukee, Wis., assignors to Bucyrus-Erie Company, SouthMilwaukee, Win, a corporation of Delaware Filed Apr. 16, 1962, Ser. No.187,483 4 Claims. (Cl. 254-196) This invention relates to an improvedfairlead and more particularly to improved guide rollers for a fairleadcarried in a fixed housing and having a frame rotatable about an axissubstantially coincident with the center line of a cable as it is guidedthrough the throat of the fairlead to a cable-winding device.

It is common practice to provide a fairlead in the association withcable-winding equipment on dragline excavators, for example. Such afairlead usually comprises a housing in which a frame is rotatablysupported for rotation about a first axis substantially coaxial with acable directed therethrough. Mounted on the frame is a pair ofdeflection sheaves for directing the cable toward a cable-windingdevice. Any angular deflection of the cable with respect to the plane ofrotation of the deflection sheaves is known as an off-lead condition andcan be compensated by rotation of the frame and deflection sheaves untilthe cable lies in the plane of the deflection sheaves.

A guide means for the fairlead is ordinarily provided to rotate theframe until the cable is substantially coplanar with the deflectionsheaves. Such guide means may comprise a pair of fixed guide platesspaced equidistantly from and parallel to the plane of rotation of thedeflection sheaves. Cylindrical roller guide means have also been usedto guide the cable toward the plane of rotation of the deflectionsheaves.

Such guide means are attached to the fairlead frame and rotate therewithabout the main axis. The rotation of the fairlead frame is occasioned bythe action of the cable being drawn over the guide means at a portion ofthe guide means away from the main axis. The primary function of theguide means is to rotate the fairlead frame and deflection sheaves sothat the cable is directed over one of the deflection sheaves.Deflection sheaves have a larger diameter than the cable and less wearoccurs between the cable and sheave than would occur between the cableand the surface of the guide means. It is therefore an advantage toprovide a guide means which rotates the frame quickly in response to anoff-lead cable condition. After rotation, the cable no longer touchesthe guide means but is aligned in the plane of the deflection sheavesand is drawn over one of the sheaves by the cable-winding means.

Previous guide means have been subjected to extreme wear and consequentgrooving at their central portions adjacent the main axis of rotation ofthe fairlead frame. Such wear can result in a single deep groove or aseries of shallow grooves in the guide means and the effectiveness ofthe guide means is virtually eliminated as the cable tends to seek theworn groove or grooves in the guide means and with the cable acting insaid worn portion there is not sufficient moment arm to rotate theframe.

The wear is most likely to occur when the cable is drawn in a lateraloff-lead condition from the fairlead, with little or no deflection fromthe main axis of fairlead rotation. Such small or negligible deflectionmeans that the moment arm of force acting on the guide means isinsufficient to rotate the fairlead.

Further, as guide means must be replaced from time to time, it isadvantageous to provide a guide means which is readily replaceablewithout occasioning lengthly downtime for the excavator, or the like.

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To avoid the problems of previous guide means for fairleads, thepreferred embodiment of this invention discloses a pair of tapered guiderollers each rotatable on axes that are parallel to one another andspaced equidistantly from the main axis of rotation of the fairlead. Thetapered guide rollers each have an enlarged central portion and theouter surface of the rollers taper inwardly toward the end portionsthereof. The rollers are spaced from each other so that a cable drawnbetween them can contact only one of the rollers at a time. Upon contactwith the tapered surface of a roller, the cable tends to slip along therotating surface in a direction away from the enlarged central portionof the roller thereby increasing the moment of the cable acting on theroller to rotate the fairlead frame about its main axis. Thus, thetapered guide rollers, with the cable acting thereon, provide for aquick rotation of the fairlead frame so that the cable is guided overone of a pair of deflection sheaves, thereby reducing the Wear on thecable and on the guide rollers.

It is therefore an object of the invention to provide a guide rollermeans for a fairlead wherein the guide roller means provides forincreasing the moment arm for rotating the fairlead when said cable isin an off-lead position.

It is another object of the invention to provide guide roller means fora fairlead wherein said guide roller means may be readily removed andreplaced without adjustment.

It is another object of the invention to provide a guide means for afairlead which reduces wear on the guide means and cable by facilerotation of said guide means to align said cable with a deflectionsheave for guiding the cable to a cable-winding device.

It is another object of the invention to provide improved guide rollermeans for a fairlead wherein cable and guide roller wear is reduced.

These and other objects will be apparent from the following descriptionand drawings of which:

FIGURE 1 is a side elevation view partially in section of the fairleadof the invention;

FIGURE 2 is a plan view of the fairlead of FIGURE 1;

FIGURE 3 is an enlarged end view in partial section taken at line 3-3 ofFIGURE 2;

FIGURE 4 is another modification of a guide roller;

FIGURE 5 is a reduced schematic elevation of the fairlead of FIGURE 1with the cable in an off-lead condition; and

FIGURE 6 is a schematic plan view taken at line 6-6 of FIGURE 5.

As shown in FIGURES 1 and 2, a fairlead 11 is provided with a fixedhousing 12 which is normally mounted in a rigid manner on a machine, as,for example, a dragline excavator (not shown). A conventionalcable-winding means 13 (FIGURE 5) is located adjacent to the fairlead.The fairlead 11 compensates for any olf-lead condition of the cable 22prior to its being wound upon the cable-winding means.

The fairlead 11 includes a main frame 14 having a rearwardly extendingtubular shank 15 supported in suitable bearings 16 carried in housing 12to permit rotation of the main frame 14 in fixed housing 12 about a mainaxis A. Normally, fairleads for the cable-winding means of draglineexcavators, logging equipment and the like, have a main axis A" which issubstantially horizontal as shown in FIGURE 1.

The main frame 14- extends forwardly of the shank 15 where parallel sideplates 17 integral therewith provide support for transverse shafts 18and 19, which lie in the same vertical transverse plane and are spacedequidistantly from the main axis A of the fairlead 11.

Rotatably supported by shafts 18 and 19 in a coplanar relationship aredeflection sheaves 2t and 21 which guide cable 22 toward a pathsubstantially coincident with the main axis A of the fairlead towardcable-winding means 13. The cable 22, at its other end, is attached to aload (not shown) which may be disposed at various locations above, belowand to either side of the main axis A. The cable 22 is drawn through thethroat 23 of the fairlead 11 and tubular shank by the winding means 13.

The parallel side plates 17 project forwardly of the shafts 18 and 19 toinclude spaced yokes 24 and 25 which may be joined together by a bridgeportion 26. A pair of guide rollers 27 and 28 are each rotatablysupported on spaced parallel axes in the 'yokes 24 and 25 respectively.

Referring more particularly to FIGURE 3, each guide roller is rotatablysupported by means of bearings 29 on each end of a central supportsleeve 30. 30 is provided with a shoulder 31 adjacent each of its endsto limit inward axial movement of the inner bearing race 32. A bearingcap 33, at each end of the guide rollers, abuts the outer bearing race34 and is demountably secured, for example, to the guide roller 27 bymeans of cap screws 35.

To support each guide roller assembly in the frame 14, a pair ofterminal support pins 36 are provided for each roller and the pairs ofpins are demountably secured through each yoke 24 and 25. By positioningthe guide roller assembly-and inserting the terminal support pins 36 ateach end of the roller within the bores 30a of central sleeve 30, theguide roller assembly may be installed. Transverse pins 37 are insertedin openings 37A of sleeve 30 wherein said pins engage longitudinallyextending transverse slot 38 of each terminal support pin to prevent anyrelative rotational movement between the support pins 36 and the sleeve30.

In previous fairleads having guide plates or cylindrical rollers forguide means, the cable must be displaced along the axis of the guidemembers a sufficient distance from the main axis A of the fairlead sothat the force exerted by the cable and acting upon the guide membercreates a suflicient moment to effect rotation of the fairlead to causethe desired alignment of the cable with the deflection sheaves. In theevent that the cable is disposed at an angle to the plane of thedeflection sheaves but is not displaced along the axis of a guide membera suflicient distance to insure rotation of the fairlead to align thedeflection sheaves with the cable, the cable tends to wear a groove atthat portion of the guide member. Continued use of the fairlead with thecable in an off-lead position results in continued wear of the guidemember and increased wear on the cable as the cable is not properlyaligned with the deflection sheaves.

To overcome this shortcoming of previous guide members, the guiderollers 27 and 28 have a large diameter central portion. The surface ofeach of the guide rollers is tapered from the central portion toward theend portions thereof. Accordingly, when the cable 22 contacts thetapered surface of one of the guide rollers 27 and 28 as the cable isdrawn in a lateral off-lead position at a slight angle from the plane ofrotation of the deflection sheaves 20 and 21, and, at a slight angleupwardly or downwardly from main axis A, the action of the cable againstthe tapered surface guide rollers 27 or 28 causes the cable 22 to movefurther along the tapered surface from the main aXis A. With the cable22 acting on the tapered surface of the guide roller the fairlead frame14 is rotated until the cable again lies in the plane of rotation of thedeflection sheaves. When this occurs, the guide roller is no longer incontact with the cable and the deflection sheaves 20 and 21 are alignedto I The sleeve d a deflection sheave is considerably less than the wearoccasiond between a guide roller and the cable, therefore, the quickerthe fairlead frame rotates in response to the off-lead condition, themore the Wear is reduced.

Such tapered guide rollers 27 and 23 provide for the facile rotation ofthe fairlead for the rapid alignment of the cable with the deflectionsheaves and thereby cable and guide roller wear is reduced.

Another guide roller it) is shown in FIGURE 4 wherein the roller 4% isprovided with a central portion 40a having a larger diameter than theend portions thereof. In a fairlead frame, a pair of rollers 40 performsimilarly to the tapered rollers 27 and 28 in that the larger diametercentral portion tends to position the cable away from the centralportion 46a to provide a greater moment arm along the axis B, so thatthe force of the cable against the guide roller rotates the fairleadabout the main axis A to place the plane of rotation of the deflectionsheaves and the cable in alignment. The wear between the cable and guideroller is reduced for the same reasons as set out above.

During operation of equipment using both a cablewinding drum and afairlead, for example a dragline excavator (not shown), the object to bepulled by the cable attached to the cable-winding drum may be disposedat various positions in relation to the fairlead resulting in anoff-lead condition of the cable. With the cable disposed at an angle tothe plane of rotation of the deflection sheaves as shown in FIGURE 6,the fairlead 11 is rotated about the main axis A by the cable acting onthe tapered surface of guide roller 28 until the deflection sheave 20 or21 receives the cable drawn therethrough in the same plane as the planeof rotation of the deflection sheaves.

In this manner, cable contact is quickly transferred from one of theguide rollers to one of the deflection sheaves, thereby reducing thewear on the cable and on the guide roller.

When replacement of guide rollers 27 and 28 is needed, it is onlynecessary to remove capscrews 41 for detaching caps 42 from each end ofrollers 27 and 28 so that the terminal pins 36 may be removed from eachend. Replacement guide rollers similar to rollers 27 and 28 alreadyassembled and adjusted are then placed in frame 14. The pins 36 arereinserted at each end of the rollers and the caps 42 are replaced. Thusthe changing of the guide rollers is accomplished quickly and simply.

Thus, improved guide rollers for a fairlead have been described whereina cable in an off-lead condition acts on the tapered surface of a guideroller at a portion of the roller surface spaced from an enlargedcentral portion of the roller to facilitate the rotation of a fairleadto position a pair of deflection sheaves to receive the cable drawntherethrough to reduce wear on the cable and the guide rollers. Theguide rollers also rotate around their longitudinal axes by the actionof the cable drawn over their tapered surfaces. The tapered surface aidsthe cable in seeking a position on the roller surface away from anenlarged central portion of the roller to occasion the cable to act onthe guide roller at an increased moment arm to quickly rotate thefairlead in the manner hereinabove described.

Having now described and illustrated two forms of the invention, it isto be understood that this invention is a .sa d f am and spacedequidistantly from said main axis and adapted to be contacted by saidcable when said cable is in an oil-lead condition; mounting mean foreach said roller comprising a central support sleeve received with eachsaid roller; demountable bearing means at each end of said sleeve forrotatably supporting a roller; a pair of terminal support pins carriedin said frame and insertable one in each end of said sleeve; and adetachable connection between each of the terminal support pins and saidcentral support sleeve.

2. The structure according to claim 1 in which said detachableconnection includes means to permit relative longitudinal movementbetween one of said terminal pins and said central support sleeve andmeans to prevent relative angular movement between said support pins andsaid sleeve.

3. In a fairlead having a frame, a pair of cable guiding sheaves mountedon the frame which are substantially co-planar and have a point on eachof their periphery adjacent one another, said frame extending beyondsaid sheaves to terminate in spaced mounting yokes, the combinationtherewith of: a pair of cable guide roller assemblies each having acentral support sleeve with hollow ends, bearings on the sleeve, aroller supported by the bearings and encircling the sleeve for rotationwith respect thereto which roller has an outer surface of maximumdiameter at its mid-point and a diminished diameter toward its ends;each roller assembly being positioned between spaced mounting yokes withits axis paralleling the plane of the sheaves and in parallel alignmentwith the other roller assembly; and support pins carried in said yokeswhich are inserted into the ends of said support sleeves to retain theroller assemblies in place.

4. An assembly as in claim 3 in which the outer surface of each rolleris a smooth taper of maximum diameter at substantially the mid-point ofthe length of the roller.

References Cited by the Examiner UNITED STATES PATENTS 1,419,049 6/22Harsel et al. 226-192 XR 3,006,608 10/61 Cirnino 254-490 3,063,680 11/62Helsel 254-190 FOREIGN PATENTS 556,728 10/43 Great Britain. 1,110,21710/55 France.

ERNEST A. FALLER, Primary Examiner.

SAMUEL F. COLEMAN, JOSEPH P. STRIZAK,

Examiners.

3. IN A FAIRLEAD HAVING A FRAME, A PAIR OF CABLE GUIDING SHEAVES MOUNTEDON THE FRAME WHICH ARE SUBSTANTIALLY CO-PLANAR AND HAVE A POINT ON EACHOF THEIR PERIPHERY ADJACENT ONE ANOTHER, SAID FRAME EXTENDING BEYONDSAID SHEAVES TO TERMINATE IN SPACED MOUNTING YOKES, THE COMBINATIONTHEREWITH OF: A PAIR OF ABLE GUIDE ROLLER ASSEMBLIES EACH HAVING ACENTRAL SUPPORT SLEEVE WITH HOLLOW ENDS, BEARINGS ON THE SLEEVE, AROLLER SUPPORTED BY THE BEARINGS AND ENCIRCLING THE SLEEVE FOR ROTATIONWITH RESPECT THERETO WHICH ROLLER HAS AN OUTER SURFACE OF MAXIMUMDIAMETER AT ITS MID-POINT AND A DIMINISHED DIAMETER TOWARD ITS ENDS;EACH ROLLER ASSEMBLY BEING POSITIONED BETWEEN SPACED MOUNTING YOKES WITHITS AXIS PARALLELING THE PLANE OF THE SHEAVES AND IN PARALLEL ALIGNMENTWITH THE OTHER ROLLER ASSEMBLY; AND SUPPORT PINS CARRIED IN SAID YOKESWHICH ARE INSERTED INTO THE ENDS OF SAID SUPPORT SLEEVES TO RETAIN THEROLLER ASSEMBLIES IN PLACE.